The invention is directed to a method and apparatus for controlling the ripening of fresh produce, particularly fresh fruit such as bananas.
Bananas and other fresh produce are typically transported from the growing fields to a processing facility where they are placed in specially designed ripening rooms. Such ripening rooms are provided with insulated, gas-tight wall and roof panels and include an air handling unit to control the circulation and temperature of the air within the ripening room. In this manner, the ripening of the fresh produce may be controlled in accordance with a predetermined ripening schedule such that the fruit is properly ripened at the time it is scheduled for delivery to retail outlets. To assist in this, ethylene gas is dispersed into the room at a preselected time to facilitate a uniform ripening of the produce. Accordingly, the use of ripening rooms enables the delivery of high quality produce to retail outlets without the constraint of having to schedule delivery in accordance with the natural ripening process of the fruit and further obviates problems associated with accelerations and decelerations of the ripening process due to changing conditions during the transportation of the produce.
In a prior ripening room arrangement, the produce was packed into unitized shipping modules comprising individual protective boxes which were block-stacked on pallets. The palletized produce was inserted into a ripening chamber having a floor, a ceiling and front, rear and side walls, which was of suitable dimensions to enclose two spaced rows of the palletized produce. The two rows were spaced apart from one another within the chamber to define an interstitial space between the rows which substantially forms a low pressure plenum. There is also provided sufficient spacing between the palletized produce and the ceiling and walls of the chamber to define a high pressure air space around and above the inserted produce load.
A tarp arrangement was placed over the top and one end of the spacing between the two rows of palletized produce to seal off the low pressure plenum from the high pressure air space. Exhaust fans were arranged in a sealed relation at the opposite end of the spacing between the rows to withdraw air from the spacing and thereby create a pressure differential between the tarp sealed plenum and the high pressure air space. Air introduced by an air handling unit is forced by the pressure differential between the high pressure air space and the low pressure plenum to flow through openings formed in the sides of the boxes, around the produce contained therein and into the low pressure plenum to be exhausted by the fans. In this manner, a forced air circulation is caused to flow uniformly throughout the produce load in the chamber to thereby uniformly control the temperature of the produce with a minimal temperature differential throughout the produce load. The temperature and flow rate of the air introduced into the chamber by the air handling unit may be accurately controlled to achieve a desired ripening rate for the produce.
A deficiency of this system, however, is that the placement of the intake and exhaust fans, at one end of the room, creates a definite length limit to the room. That is, the air handling unit may only accommodate a predetermined number of pallets of produce. While the use could conceivably lengthen the room, the ability of the air handling unit to effectively remove the air from a larger room, and at a farther distance away, would be severely compromised.
There is a need for a ripening system which may be easily expanded to allow the ripening of even larger amounts of produce. There is further a need for a ripening system which dispenses with the complicated tarp arrangement.